In recent years, system-on-a-chip (SoC) that integrates most of the system onto a single large scale integration (LSI) has become widespread because of high packing density achieved by miniaturization of semiconductor manufacturing processes. Comparing SoC with a plurality of single function LSIs mounted on a substrate, SoC offers a number of advantages including reduced footprint on a printed circuit board, higher speed, lower power consumption, and reduced cost.
For example, a system-on-a-chip has been proposed that includes a hard macro block, a power control section, and a multi-threshold complementary metal oxide semiconductor (CMOS) logic circuit (PTL 1). The system-on-a-chip can reduce leak current in the system-on-a-chip as a whole by powering off the hard macro block.